The invention relates to a pump provided with diaphragms, and more particularly, to a compact pump which is used for a sphygmomanometer or the like.
A related-art compact pump of this type is now described by reference to FIGS. 3 and 4. As shown in FIG. 3, a compact pump 1 used for a sphygmomanometer or the like is provided with two diaphragms 4 constituting pump chambers 3 within a case 2 which is of rectangular parallelepiped shape when viewed from the top. The diaphragms 4 are integrated, thereby constituting a diaphragm assembly 5.
A substantially-cylindrical vent valve section 6 is provided in an upright position in the center of the diaphragm assembly 5. The vent valve section 6 is press-inserted into an interior wall of a vent hole 8 drilled in the center of an upper case 7.
Intake valves 9 are provided in positions on the upper case 7 which are located above and aligned with centers of the respective diaphragms 4. Portions of the intake valves 9 facing the pump chambers 3 are formed into sealing sections 9a. The intake valves 9 are passed through small holes 10 drilled in the upper case 7. Stopper sections 9b which are larger in diameter than the small holes 10 are formed in the upper face of the upper case 7. The sealing sections 9a are brought into pressing contact with a lower face of the upper case 7. Several intake holes 11 are drilled in the vicinity of the peripheries of the small holes 10, and the sealing sections 9a of the intake valves 9 seal the intake holes 11.
A pivotable member 12 is pivotally joined to lower ends of the diaphragms 4. The pivotable member 12 is constructed so as to pivot, by an eccentric shaft 13 which rotates. More specifically, an upper end of the eccentric shaft 13 is fitted into an insertion hole 14a formed in a boss section 14 formed so as to protrude downward from the center on a lower face of the pivotable member 12. A lower end of the eccentric shaft 13 is loosely fitted into an eccentric hole 15a eccentrically formed in a rotor 15. The rotor 15 is secured on an end of a rotary shaft 16 of a motor (not shown).
FIG. 4 is a bottom view of the upper case 7. Formed in the bottom face of the upper case 7 are the vent hole 8 and vent grooves 17 for establishing communication with the pump chambers 3 provided in the diaphragms 4.
The rotary drive shaft 16 of the motor rotates, whereupon the rotor 15 rotates. In turn, the eccentric shaft 13 loosely fitted into the eccentric hole 15a of rotor 15 is rotated, whereupon the pivotable member 12 undergoes pivotal movement, to thereby vertically actuate the lower ends of the diaphragms 4. When the lower end of one of the diaphragms 4 is lowered by the pivotable member 12, the inside of the diaphragm 4 assumes negative pressure, and the vent valve section 6 seals the vent hole 8. Further, the sealing section 9a of the intake valve 9 is opened, thereby enabling inflow of air by way of the inlet hole 11.
Next, when the lower end of one of the diaphragms 4 is actuated upward, the inside of the diaphragm 4 assumes high pressure. The sealing section 9a of the intake valve 9 brings the inlet hole 11 into a sealed state, releasing the space between the vent valve section 6 and the vent hole 8. The air of the pump chamber 3 is discharged to the outside from the vent hole 8 by way of the vent groove 17.
In the related-art compact pump, it is necessary to provide intake valves 9 which are individual members, to drill the small hole 10 and the intake holes 11, and to take care of position matching of the sealing portion 9a of the intake valve 9 and the inlet holes 11. Hence, the numbers of parts and assembling operations are accordingly increased, thereby total cost is also increased.
It is therefore an object of the present invention to provide a pump provided with diaphragms, in which a decrease in the numbers of parts and assembling operations by use of a simple construction to thereby enable cost cutting.
In order to achieve the above object, according to the present invention, there is provided a pump, comprising:
a casing body formed with a vent hole, the casing body having an inner face formed with a plurality of grooves respectively communicated with the vent hole;
a plurality of diaphragms, respectively inserted into the grooves to form a plurality of pump chambers; and
an actuator, which actuates the diaphragms to compress or decompress the pump chambers.
Preferably, the actuator is formed with a plurality of intake holes, and each of the diaphragm is provided with an intake valve section communicated with an associated one of the intake holes.
Here, it is preferable that the intake valve section is a flap member formed by incising a part of each diaphragm.
In the above configurations, since the grooves into which the diaphragms are inserted form a part of the vent hole, it is not necessary to separately provide such a member as the intake valve member shown in FIG. 3, and to separately drill such holes as the intake hole and the vent groove shown in FIG. 4, thereby, enabling a decrease in the numbers of parts and assembly operations by use of a simple structure and in turn enabling cost cutting.